Protector for dipper doors



NOV- 20, 1934 n' G. B. HEFFELFINGER 1,981,257

PROTECTOR FOR DIFFER DOORS Filed May 3l, 1954 Patented Nov. 20, 1934 UNITED STATES PROTECTOR FOR DIPPER DOORS Glen B. Heffelfinger, Marion, Ohio, assignor to The Marion Steam Shovel Company, Marion, Ohio, a corporation of Ohio Application May 3l, 1934, Serial No. 728,341

19 Claims.

This invention relates to excavating dippers and more particularly to a protector for the door of such a dipper.

In certain types of excavating dippers the open,

l spoil receiving, end of the dipper faces upwardly during the excavating operation and the opposite end of the dipper is closed by a door which is hinged to the body of the dipper and held in its closed position by a latch, to enable the door to be released to dump the load. Frequently rocks or chunks of heavy hard material will fall into the dipper before any substantial quantity of spoil has entered the same. If such a rock falls from any vconsiderable height and strikes the dipper door the force of the impact is often such as to cause injury to the doorvand to the dipper as a whole. In the larger sizes of dippers a rock of great weight can enter the dipper and may strike the door with suicient force to break the hinge straps or other reinforcing bars. lIi the rock has a sharp corner or edge it may pierce the door. Even when such serious injuries are not caused the impacts from such rocks or other material striking the door deform the same and tend to loosen the rivets and joints not only in the door but in the dipper as a whole. Further, when the door is released to dump the load the heavy mass of material in the dipper slides over the face of the door as the latter moves toward its open position and the abrasive action of this heavy load causes severe Wear on the door which in the handling of certain classes of material will destroy the door within a comparatively short time. It has been proposed to provide the door with a metal wear plate which can be renewed when worn out, without discarding the door as a whole, but even the removal of a worn wear plate and the attaching of a new wear plate involves a heavy expense. One object of the invention is to provide such a dipper door with a protector which will so cushion the force of the impact of a falling object striking the door as to prevent injury to the door or to the dipper as a whole.

A further object of the invention is to provide such a protector which will distribute the force of the impact over a relatively large area of the door and thus greatly reduce the likelihood of injury to the door.

A further object of the invention is to provide such a protector of material which will not be seriously aiected by the impact of falling objects or by the abrasive action of the material discharged from the dipper.

55 A further object of the invention is to provide such a protector with means whereby it may be readily attached to and detached'from the door.

Other objects of the invention will appear as, the device is described in detail.

In the accompanying drawing Figi is a top plan View of a dipper door showing the protector applied thereto and partly broken away; Fig. 2 is a section taken on the line 2-2 of Fig. 1; Fig. 3 is a section taken on the line 3-.3 of Fig. 1; Fig. 4 is a detail sectional view of a portion of the protector; and Fig. 5 is a side elevation oi the dipper, partly broken away, to show the protector within the same.

In the drawing I have illustrated one embodiment of my invention and have shown the same as applied to the door of a dipper of the type commonly employed on power shovels but it will be understood that the protector may take various forms and may be made of various materials and that it may be applied to the doors or corresponding parts of dippers or scoops of various kinds.

In the construction shown the protector is of a laminated construction and comprises an upper layer or lamination of cushioning material and a lower lamination of supporting material. Preferably there'are at least two laminations oi' cushioning material and an intermediate lamination of resilient material but a Single layer of a proper cushioning material secured directly to the door would have a substantial cushioning action and would provide the desired resistance to abrasion. Any suitable cushioning material may be used but I prefer to employ rubber, as certain grades of rubber, particularly rubber of the quality and texture used in the treads of automobile tires, has not only a substantial cushioning action but is strongly resistant to injury by either impact or abrasion. The resilient materialmay also be of any suitable character but I prefer to employ sheet metal. In the particular construction shown the protector comprises an upper layer 6 of rubber, a plate 7 of sheet metal, a second layer 8 of rubber and a supporting plate 9 which may also be of sheet metal. The sheet metal is relatively thin and the several laminations may be firmly attached one to the other in any suitable manner but preferably this is accomplished by vulcanizing the `rubber on the metal plates. While I have shown four laminations it will be understood that any desired number of laminations may be employed.

The protector thus formed is secured to the inner side of the door and when a rock or other heavy object dropsinto the dipper it will strike the upper layer of cushioning material which will yield under the force of the blow and will depress the resilient intermediate lamination 7. The depression of this resilient material will displace a relatively large amount of the cushioning material of the lower layer and will thus cause the force of the blow .tofbe distributed over a large area of the door, thereby minimizing the likelihood of seriousl injury to the door. Rubber of the character referred to is not easily broken or pierced even by a sharp corner on a rock, and even should the upper layer of rubber be pierced or broken through there is very little likelihood of the sheet metal layers and the lower rubber layer being pierced and consequently there will be no danger whatever of the door being piercedor broken. I haveV in the present instance shown the protector as having an area approximately equal to the area of the door, it being spaced from the edges of the door just far enough to permit the door to be closedand the protector toenter the body of the dipper.- However, it is seldom that any large or heavy rock `or the like entering a dipper will strike the marginal portions of the door. It will usually strike largely or entirely on the central portion of the door. Therefore it is not essential that the lprotector shouldcover the entire area of the door which lies within the bounds of the dipper walls but very satisfactory protection can vbe had by use-of a protector having an area substantially less than the area Of the door.

The protector may be attached to the door in any suitable manner but it is preferably detachably secured thereto. In the present construction the function of the lower plate of sheet metal 9 ls principally that of a supporting member which provides a convenient means for attaching the cushioning elements to the door. As here shown,

the supporting plate 9 is provided with a Series of openings 10 to receive fastening elements passed through the door, which is shown at 11 and is v supported by the hinge arms 12. The supporting plate being of thin material would not ordinarily accommodate screw threads sufficient in size and number forthe purpose and I have therefore arranged on the upper side of the supporting plate, in proper relation to the openings l0, fastening elements, here shown as nuts `13, which are adapted to be engaged bycooperating fastening elements, such as bolts 14, extending through the door 11 to rigidly `connect the plate, and consequently the protector as a whole, to the door. In order that the fastening elements or nuts 13 may be permanently supported in proper alinement with the openings 10 I haveprovided means for temporarily securing them to the supporting plate prior to the assembling of the several elements of the protector and for holding them in position during the assembling and vulcanizing of thev protector. For thispurpose studs 15 are mounted in the openings 10 and threaded into the nuts, prior tothe assembly of the protector. these studs being provided with kerfs 16 to re-v ceive a screw driver forv removing the same. When the layer 8 of rubber is vulcanized to the supporting plate 9 each nut will be embeddedr in the rubber and will therefore be held firmly in its proper position by the rubber, thus permitting the retaining device or stud l5 to be removed at any time after theprotector has been completely assembled.

While I have shown and described one embodiment of my invention I wish it to be understood that I do not desire to be limited tofthedetails thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. A protector for a dipper door comprising a layer of rubber secured to the inner side of said door and of suflicient thickness to form a cushion.

2. A protector for a dipper doorcomprising a layer of rubber secured to the inner side of said door and having a smooth wear resisting surface.

3. A protector for a'dipper door comprising a layer of rubber of sufficient thickness to form a cushion andhaving a smooth wear resisting surface, and means for securing said rubber to the inner side of said door.

4. A protector for a dipper door comprising a layer of rubber, a metal plate secured to said layer of rubber, and means for securing said metal plate to the inner side of the door.

5. A protector for a dipper door comprising a layer of cushioning material, a metal plate firmly secured to said cushioning material and having openings therethrough, and attaching elements embedded in-said cushioning material adjacent to the respective openings and adapted to be engaged by other fastening elements inserted through said door and the openings in said plate. v

6. A protector for a dipper door comprising a layer of rubber, a metal plate to which said rubber is vulcanized, said plate having openings therethrough, and nuts embedded in said rubber in line with the respective openings in saidplate to receive bolts inserted through said door'and said openings. v

7. A protector for a dipper door comprising superposed layers of cushioning material, a plate of resilientmaterial arranged between and se cured to said layers of cushioning material, and means for attaching one-of said layers of material to the inner side of said door.

8. A protector for a dipper door comprising superposed layers of cushioning material, a plate of resilient material arranged between and secured to said layers of cushioning material', a second plate secured to the outer side of vone of said layers of cushioning material, and means for securing said second plate to the inner side of said door.

9. A protector for a dipper door comprising superposed layers of cushioning material, a plate of resilient material arranged between and secured to said layers of cushioning material, afsecond plate secured to the outer side of one ofsaid layers of cushioning material, and having openings therethrough, attaching elements arranged on the inner side of said second plate and held by the adjacent layer .of cushioning material in positions in which they may be engaged by other attaching elements inserted through said door and saidv openings.

l0. A protector for a dipper door comprising a supporting plate having anv opening therethrough, a fastening` element on one side of said plate, a device mounted in said opening and engaging said fastening element to retain the same temporarily in a Xed position with relation to said opening, and cushioning material secured to said plate and engaging said fasteningelement to retain the same permanently in said -Xed position, said retaining device being removable after said cushioning material has been securedto said plate to permit a second fastening element to be rst mentioned fastening element.

inserted through said opening and to engage the 1l. A protector for a dipper door comprising a supporting plate having an opening therethrough, a nut arranged on one side of said plate in line with said opening, a stud mounted in said opening and having screw threaded engagement with said nut, and a layer of rubber vulcanized to said plate and engaging said nut to retain the same in line with said opening, said stud being removable to permit a bolt to be inserted through said opening and to engage said nut.

12. A protector for a dipper door comprising alternate laminations of rubber and sheet metal.

13. A protector for a dipper door comprising alternate laminations of rubber and sheet metal firmly attached one to the other, and means for securing one of said laminations to the inner side of said door.

14. A protector for a dipper door comprising a plurality of laminations of cushioning material,

l and metal, the upper lamination being of rubber and the lower lamination being of metal, and means for securing said lower lamination to the inner side of said door.

15. A protector for a dipper door comprising alternate laminations o'f rubber and sheet metal vulcanized one to the other, the upper lamination being of rubber and the lower lamination being of metal, and means carried by said lower lamination to engage fastening elements extending through said door.

16. A protector for a dipper door comprising alternate laminations of rubber and sheet metal vulcanized one to the other, the upper lamination being of rubber and the lower lamination being of metal, and having openings therethrough, and nuts supported on the upper side of said lower lamination in line with the respective openings and adapted to receive bolts inserted through said openings.

17. A protector for a dipper door comprising a layer of cushioning material secured to the inner side of said door, and a metal plate arranged above and supported by said cushioning material.A

18. A protector for a dipper door comprising a layer of cushioning material secured to the inner side of said door, a metal plate arranged above and supported by said cushioning material, and a layer of yieldable material arranged above and supported by said metal plate.

19. A protector for a dipper door comprising a layer of cushioning material secured to the inner side of said door, a metal plate arranged above and supported by said cushioning material, and a layer of yieldable material arranged above and supported by said metal plate, said yieldable material having a wear resisting upper surface.

GLEN B. HEFFELFINGER. 

